Defence of The Anciets (DoTA) needs no introduction. The multiplayer role- playing- game, created by Valve Corporation, has been a phenomenon ever since its inception. Not to mention, this game remains as one of the most followed ones, with tournaments held at prizes upto 24 Million Dollars!

This insane fan following and hype about the game inspired a team of developers from OpenAI to develop a bot which will act as a player competing with the best DoTA 2 players in the world evenly, or even better than them.

Doing the seemingly impossible task

DoTA is an extremely complicated game. One can never win with just the help of a rule- book kept open beside him. Strategy and timing are the most important factors which decide the flow of tide of the match. Expert players usually have a great command over their chosen hero and are adept in planning, attacking, tricking and deceiving their opponents at the right time. Obviously, just feeding the bot with all the rules was not going to make it a master of the game.

The team at OpenAI decided to try another approach. They started with a normal bot, completely ignorant about the DoTA world and rules and put it against an exact copy of itself in a 1 vs 1 match. With this, they ensured that the AI bot is training against another player which is a complete match for the bot in terms of playing strategy and experience. Slowly and steadily it climbed the skill ladder match after match until it reached a level which can compete with the best professional level DoTA player in the world. It all learnt via self- play to predict where other players will move, improvised in response to unfamiliar situations and influenced the other player’s allied units to help it succeed. The end result is totally remarkable!

The bot was tested with professional players of the game at The International- the largest platform of DoTA 2 which invites highly skilled players from around the world to compete for massive prize money. The AI bot had learned really robust moves and strategies which outdid even the pros. Many of them even wanted to keep the bot with them as that would help them improvise themselves for further tournament editions. The AI bot has been successful.